Signal system



A. E. MEYER.

SIGNAL SYSTEM.

APPLICATION FILED FEB. II. I918.

Patented Apr. 19,- 1921.

series.

Ailiihii ALFRED E. MEYEE, OF CINCINNATI, OHIO.

SIGNAL sYscrEM.

Specification of Letters Patent.

Patented Apr. 19, 1921.

Application filed February 11, 1918. Serial No. 216,561.

T 0 all whom it may concern Be it known that I, ALFRED E. MEYER, acitizen of the UnitedStates, and residing at Cincinnati, in the countyof Hamilton and State of Ohio, have invented a new and usefulImprovement in Signal Systems, of which the following specification is afull disclosure. i

My invention relates to an electric system for the transmission ofsignals as of central station alarm service or watchmens time recording.V

The invention has for an object the provision of a signal system with ametallic service line extending from a centralor receiving station tothe transmitting stations and back to the receiving station, with thetransmitters of said transmitting stations in series circuit connectionwith said metallic line, and with a ground connection under automaticcontrol dividing the transmltting stations into a plurality of serviceor signal transmitting branch lines, each with an earth return circuit,whereby the advantages of a continuous metallic. line between thereceiving and. transmitting stations is available. 7

Another object of the'invention is to provide a plurality of signalsystemsfor central station alarm service, each system comprisingreceiving apparatus and transmitting I apparatus connected by ametallicpartial circuit line and ground return, and a line controlling device inconnection with the metallic lines of said systems for establishing theearth return for said metallic lines, automatically operated byachangein current strength from the normal for establishing a metallic.line and receiving station connection between the metallic lines of thedifferent systems in the event of an impairment to one of said metallicservice lines.

Another object of the invention is'to connect the ends of centralstation metallic partial signal circuit lines, with a circuitcontrolling device uninfiuenced by the normal current strength carriedby the circuit lines, but responsive to a definite increase of currentstrength for bringing a portion of an impaired service line intocommunication with the central station over and in direct circuit with asecond normal service line, and for reestablishing the independence ofthe service lines when the'impairrnent to the one has been rectified. p

1 Other features and objects of the invention, combination of elements,and arrangement of parts w1ll be more fully hereinafter described, andmore particularly pointed out in the claims. convenient embodimentgistypically. illustrated in the accompanying drawing, forming a parthereof, and in the drawing like characters of reference denotecorresponding parts throughout the several views, of which:

Figure 1 is ardiagrammatic view of an electric signal system with thevarious appliances connected in electric circuit under a normalcondition.

Fig. 2 is a diagrammatic view of a modified form of wiring and'circuitcontrolling apparatus.

As the system primarily is contemplated for a central station nightwatch time recording or fire alarm signal service, the description willgenerally be confined to this particular field of use, although as tocertain aspects other kinds of electric signal systems are comprehended.

A closed metallic circuit for the trans mission of signals may bedesignated as a continuous line starting froma central station orreceiving point, including in series the various and diii'erenttransmitting devices embraced in the system and returning'to the centralstation; 1 An open earth return circuit is utilized in connection withthe metallic line for transmitting trouble signals. This assuresnormally thetransmission'otwtwo signals usually distinctive in characterfrom each point or transmitting device, and provides a means formaintaining the system under test, and also a means for transmitting asingle or ground circuit signal in the event of a break in the metallicline, dividing the transmitting devices of the series with those on oneside of the break using one portion of the metallic line, and those onthe opposite side of the break using the other portion of said metallicline. Limitations as to the number of transmitting devices under suchsystem are placed by insurance underwriting authorities, as aprecautionary measure.

' With my system the advantages above noted in a complete or all closedmetallic circuit'system are maintained, but the metallic line,whenconditions are normal, is divided into independent'service lines, eachfor successively transmitting signals over two independent circuits bothhaving earth return, so thatin single loop line, the

.requirea difierent or greater current inorder to be attracted by theirmagnet coils over those of relays 1, 2. Thus, under a closed circuit andnormal line, relays 1, 2, will stand with their armature leversattracted to their magnets or closed while relays l", 2, will stand withthese armature levers retracted from their magnets or open. 3 indicatesa generator, or source of electric energy supply, and 4:, 5, tap keyswitches for respectively cutting out the relays of the differentservice lines, and located at the service or receiving station.

The relays represent those of commercial I type used in pen recorders,and in general comprise a magnet coil 6, armature lever 7, which as apole switch, in its to and fro motion, alternately contacts with therelatively opposite terminals 8, 9, for making and breaking electriccircuits.

The armature lever is held under tension by a spring 10, which in allrelays is arranged, so that i'ts tension may be adjusted or varied.

The tap key switches at and 5 are the duplicate of each other, and eachcomprises a key lever 11, swung between two relatively oppositeterminals 12, 13, and under tension by a spring 1a to normally engageorcontact with one terminal in this instance terminal 12.

15,15, 15, represent break wheel signal transmitting devices ot onegroup located at different service points from the service or centralstation, and may be designated as night watch boxes as of a type ofconstruc tion, wherein the break wheel is manually started or set inmotion by an operator turning a key, and 16, 16, 16, signal.transmitting devices oi? a second group. The number for either group isoptional, and in a general way they may be described as switch devicesoperated by a break wheel, so that one transmitting device is capable oitransmitting a signal distinctive over the signal of the other signaltransmitting devices. matic, as for automatic fire alarm service. Forthe present purpose, each of the tran mitting devices comprises a breakwheel 17 flexible switch fingers 18, 19 and 20, each finger having acontact or terminal point Their operation may also be autoengaging withthe contact point ofthe ad jacent linger for completing the circuit,through the connected fingers. The finger 18 is extended to engage withthe break wheel 17, and its contact point with a registering contactpoint projected from finger 19, and likewise finger 19 arranged forelectrically connecting with the finger 20.

The break wheel 1'? is notched or toothed for a proper finger control totransmit in each revolution a definite signal' Each break wheel, under anormal condition of the system rests with the break finger 18 engagingits periphery at a point which will hold the contact point of saidfinger in engagement with the contact point ofan adjacent finger 19 forcompleting a partial line circuit through'said fingers l8 and'19. A

third break finger 20, adjacent the break finger 19 normally has itscontact point free from engagement with the finger 19 so as not to be inelectric circuit therewith. Finger 20 of each call box connects with awire 21 leading to a ground terminal 22.

At a. terminal or meeting point of the metallic service lines 43,'eachservice line' including in series wiring the fingers 1'8 and 19 of eachcall box or signal transmitting device, a circuit controlling device isprovided and operated from the central station over one of the servicelines it a break occurs in the other. The controlling device couplingsuch portion of the broken service line between the point'of break andcircuit controlling device to the other intact service line to bring itin circuit with the central station, until the line is rectified.

The circuit controlling device, as shown in F 1, comprises a pluralityof flexible fingers 25, 26, 27, and adjacent one another, each mounted.upon an insulator base or support. l ingers 25 and 27 are connectedtogether to move as a'unit but electrically insulated from one another,with finger 27 having a contact point adapted to connect or engage 28.Fingers 25 and 26 are arranger to connect with each other throughcontact points which normally are engaged. 29 indicates a trip leveractuated by a spring 30 after the lever has been tripped by anarmatrouble of broken service ture 31 when attracted to its magnet 32.33

and 3 1 each indicate a resistance.

I .l-Vz'ring diagram.

The circuits to and from the various terminals of the devices abovedescribed may be traced as follows: I

Commencing at the generator or source of electric supply 3, one end of awire or lead 35 connects with one pole oi the gen erator, and itsopposite end connects with the earth at 36. A wire 37 connects to theopposite poleof the generator as a main para contact point of fingertial circuit metallic lead line for the various service lines orbranches. Each branch or service connects with the main lead line 8? atthe central station and may be said to consist of a station line and afield line normally connected by afitap key switch 4. As the differentseries lines are the duplieate of each other, it is only necessary to describe one in detail, each however running from the central station andterminating at a common point'at which the field circuit controller islocated so as to connect therewith. r 1

Therefore describing the service line, which includes the relays 1, 1and transmitting device or call boxes 15, it may be said to comprise astation service line 38. The station service line 88 connects at one endwith the main lead line 37 and itsoppo site end with the contactterminal 12 or the tap key switch 4. This station service line '88includes in series circuit connection therewith a resistance 40, andrelays 1 and 1. The metallic circuit line 39 connects at one groundcircuit from finger direct to the central station ground terminal,cutting out the resistance 33, causing a rise in the current sunicientto fully energize the windings of the relay 1 The armature lever of therelay 1 is operated for a primary signal indication orrecording. Thebreak wheel continuing for afinger control breaks the connection or"fingers 18, 19, which breaks 01' opens the circuit causing the magnetwinding of relay- 1 to become deenergized fora secondary signalindication on record. Such make and break, in a particular order,

commencing and continuing for a double indication or recording ofadistinctive signal.

The armature 7 of the relay 1 for the primary si 'nal is operated orvibrated by variations in the current strength through an operatingcall-box. The armature is attracted to its magnet when the circuit isend with the key lever '11 of thetap key switch 4 and under normal linecondition includes in series'circuit connection the fin gers' 18, 19, ofeach transmitting device or call box 15 and'conn'ects with theresistance 33 at its opposite end. From the resistance, metallic circuitline continues through a wire 42 connecting with a terminal e3 as acommon terminal for the various metallic I circuit lines ofthe differentservice branches.

The common terminal 43 connects with the one pole of the windings of themagnet 82 and the opposite pole of said magnet windings connect with awire 14:, which extends to and connects with the finger of the circuitcontrolling device. The circuit thus continues from finger 25, throughfinger 26, wire to the ground 46. The constant resistance in the serviceline reduces the current flowing.therethro'ugh preventing the fullenergization of the magnet windings of relay 1 and magnet 32 of thecircuit controller device or anexcitation sufiicient to attract theirrespective armatures. Thus closed signal circuits are maintained fromthe source of electric supply through the said devices insaid servicelines 38, 89, re-

established through the break fingers 18 and 20 of the operatingcall-box, connecting the field line or wire 89' and ground return, towhich the finger" 20 connects. This shunts the resistance 88 resultingin an increase in current strength to relay l andanincrease in thedegree of its magnet pull," which overcomes the spring normally holdingthe armature away from its magnet. instantly upon breaking the contactbeytweenthe fingers 18 and 20, the circuit is reestablished through theresistance 33, lowering the current strength and thereby the pull of themagnet of relay 1, making the spring force prevail over the pull of themagnet to swing the armature to its retracted position; Thearmature ofthe relay 1 is normally held attracted to its magnet and for receivingthe secondary signals is vibrated by making and breaking the circuitturning through'the earth from the ground terminal 16 to the generatorground termical 36. V

For the transmission of a call signal, it may be assumed that the breakwheel 17 of a given coil box 15 is rotated, and depending upon itsparticular signal indicating cut, will, sem'mtc'm, move the finger 18 tobring the contacts of all fingers 18, 19 and 29 into engagement Thisshort circuits or shunts the portion. of the metallic circuit line fromsaid call boxto the ground connection of the circuit controlling deviceat the end f e line an C mpletes a partial movement of finger 18 awayfrom finger 19.

Now assume that a break or ground occurs in the circuit line 39, say atapoint indicated by the cross, which would be observed at the centralstation,"a break affecting relay 1, which would becoine deener gized,releasing its armature lever showing that the condition of the fieldline 39 has been disturbed, a break in the circuit would leave thetransmitting devices or call boxes 1'5, 15, beyond such break out ofconnection with the central station. The operator would thereuponimmediately throw the tap key 5 to connect line 39 in circuit with theture lever 31, tripping the trip lever 29,

which will close or connect fingers 27, 28, and break fingers 25 and 26,thus connecting such portion of the field service line 39 beyond'thebreak X in circuit with the field service line 39, as follows:

Commencing with the terminal 50 at the I end of the field service line39, through a wire 51, connecting with the finger 28, through saidfinger 28 connected therewith through said finger 27 and wire 52,connecting with the terminal 53 at the end of the field service line 39,which cuts out the resistance 33 and 34;, coupling such broken portionor" the field service line 39 with the central station, through asecondbranch. After the trouble in the service line 39 has been corrected, thetrip lever 29 is manually swung and engaged with the armature lever 31,breaking the circuit connection between fingers 27 and 28, and againestablishing a circuit connection between fingers 25, 26. The serviceline for relays 1 and l is likewise provided with a shunt line 54,connecting with the main lead line 37 and adapted to be thrown-incircuit with the field service line 39 by the tap key 4:, to out out therelays 1 and 1 and resistance 10 for operating or energizing thewindings of magnet 32 in case of a break in the field service line 39 tothrow such portion of the line broken from communication with thecentral station, in circuit with the field service line 39. A momentaryoperation of the tap keys a and 5 is only necessary for energizing themagnet 32, and to transfer a portion of one service line in circuit witha second service line, so as not to interfere with the sending ofsignals from the call boxes in communication with the relays of thefirst branch, or vice versa, as the case may be. Thus, a signal from allthe call boxes can be received at the central station. In the diagram,Fig. 2, the circuit controls ling or transfer device represents amodified form adapted to be reset from the central station, and indetail comprises the following parts The two service branch lines 39-39%as in Fig. 1,. lead to the circuit controlling or transfer device, withservice line 39 connecting with one pole of a magnet winding 32, 7

its opposite pole connecting by a wire to a finger 61, normally as anopen line circuit.

The wire 60 through abranch connection connects with the resistance 33,thence by a wire 62 connects with the circuit. breaking sector 63mounted upon a shaft 64: of an'ordinary clock movement commonly used infire or alarm call boxes. A finger 65 normally engages the circuitbreaking sector 63 and is grounded. The second service line 39 connectswith one pole oi a magnet winding 32 The opposite pole of said magnetwinding 32 is connected to a wire 66 which leads and connects to a breakfinger 67 adapted to engage the circuit breaking sector 63. line 66connects by a branch with the resistance 34% at one side orpole, whilethe opposite pole of the resistance connects with the wire 62 leading tothe circuit breaking sector 63. 68 represents an armature for trippingthe clock movement escapement 69 for releasing the circuit breakingsector 63 when either one of the magnet windings 3232 have been fullyenergized to attract the armature 68. .Under normal conditions of thesystem, the circuit in the service line 39 is closed from the centralstation through said line magnet 32, resistance33, wire 62, circuitbreaking sector 63, break finger 65, returning through the ground. Thus,the resistance 33 is included in the circuit, which reduces thepotential to a degree preventing lull energization of the magnet winding32. When it is necessary to transfer or 0011- 7 nect the serviceline 39with the service line 39, a proper tap key at the central office isoperated to cut out the resistance and relays connected in the serviceline 39, thus fully energizing magnet 32 tripping the escape ment andpermitting the circuit breaking sector to rotate one-half oi therevolution to break the circuit connection between fingers 65 andcircuit breaking sector 63, .and connect the breaking fingers 61 and 67with the circuit breaking sector 63. In such position of the circuitbreaking sector63 the service line 39 will connect or be coupled to theservice line 39, through the magnet winding 32, wire 60, contact finger61, circuit breaking sector 63, contact finger 67, wire 66, magnetwindings 32-"% to service line 39*. Under such conditions theresistance33 and 34 will be cut out. The magnet windings 32and 32 remainconstantly in circuit with the service line communicating with thecentral office for test and reset purposes, which, as soon as the lineconditions have been corrected, either one of the tap keys may beoperated to throw in a higher potential in the service linesenergizingthe magnets 32-32 tripping the escapement for a sec- 0nd halfof revolution of circuit breaking sector 63, permitting it to breakconnection with the fingers 6167, and reestablishing its connection withthe break fingers 65. Thus, the service lines may be connected forsignal transmission over one of them at ing one pole thereof connectingwith said.

metallic line and the opposite pole grounded, a resistance interposed insaid line, a ground connection between the ends of the resistancedividing said metallic line into independent service circuits having anearth return, a relay for each service line in circuit therewith andconnected in series circuit connection with said metallic line, and acircuit controller for shunting said resistance and cutting out theearth return.

2. In a signal system, comprising a me tallic line, a source of currenthaving one pole thereof connecting with said metallic line and theopposite pole grounded, a resist- ,ance interposed in said line, signaltransmitting apparatus in circuit with said me tallic line, a groundedconnection interposed in said resistance between the ends thereof fordividing said metallic line into independent circuits, each having anearth return, a relay for each service line in circuit therewith, andelectro-magnetic means having its magnet windings normally in circuitwith said independent service lines for shunting said resistance andestablishing a unitary metallic line.

3. In a signal system, comprising a metallic line having its endsconnecting with a common pole of a source of electric current, a sourceof cu rent having one pole grounded, transmitter and receiving devicesin series circuit connection with said metallic line, a resistance insaid line, and a switch device having one pole connecting with saidresistance intermediate of its ends, and an opposite pole grounded fordividing said line into series circuit with the ground return andalternately for shunting said resistance.

4. In a signal system, comprising a metallic line, a source of currenthaving one pole thereof connecting with the ends of said metallic lineand the opposite pole thereof grounded and earth connection for saidline for dividing said metallic line into independent circuits, eachhaving an earth return, signaltransmitting apparatus for eachindependent circuit in circuit there'- with, receiving apparatus foreachindependent circuit in circuit therewith, and electromagnetic meanshaving its magnet windings normally in circuit with said independentservice lines for cutting out said earth connection and establishing aunitary metallic line. I

5. In a central station signal system, a pair of metallic circuit linesextending from the central station for a partial circuit, having acommon earth return connection, a source of current having onepolethereof connecting with one end of said circuit lines,

and its opposite pole grounded, a resistance respectively for each ofsaid service lines,

signal transmitting apparatus respectively ground return, a source ofcurrent having one terminal connecting with said metallic lines and itsopposite terminal grounded, a plurality of signal receiving relaysoperated by different strengths of current, for each line, signaltransmitting devices having a ground connection adapted when out incircuit with said line to shunt said resistance for changing the currentstrength for successively operating said relays, and a switch device forsaid metallic lines for connecting said lines to a ground return andalternately breaking said ground return and connecting said metalliclines.

In witness whereof, I hereunto subscribe my name, as attested by the twosubscribing witnesses.

ALFRED E. MEYER.

Witnesses: I

CLARENCE B. Fosrn-R, MILDRED SMITH.

